Well rotor



Feb. 22, 5; uss

WELL ROTOR Filed 001:. 2, 1963 Fig. 1.

INVENTOR. John E. Russ BY W MM 5m #MM United States Patent ()filice 3,236,320 Patented Feb. 22, 1966 3,236,320 WELL ROTOR John E. Russ, Rte. 1%, Bloomington, Ind. Filed Oct. 2, 1963, Ser. No. 313,280 4 Claims. ((31. 175263) This invention relates generally to earth drilling devices and more particularly to a reamer adapted to enlarge Wells drilled through rock formations.

In certain localities water wells are drilled through a top layer of soil and into the underlying rock, such as limestone. In the majority of cases a 4 inch or 6 inch hole is drilled through the soil and into the limestone, and a steel casing is extended through the soil and into the rock formation but not to the full depth of the drilled hole. It frequently happens that water does not flow into the lower portion of the drilled hole at a rate comparable to the pump capacity and, consequently, the pump will fail to provide more than or gallons of water during any single pumping period. Consequently, the over-all capacity of the well is insufiicient to provide the demands of the pumping system.

There are known reaming devices adapted to enlarge well bores, but in many cases such devices are quite expensive and require complex apparatus for their operation. Also, the known reaming devices often fail when they are operated through stone strata of excessive hardness and also when the stone strata is cracked. The cracks seem to cause excessive stress on the conventional reaming devices so that various components of the reamers fail completely or become otherwise inoperative.

Accordingly, the principal object of this invention is to provide means for enlarging well bores which comprises simple structure adapted to operate in rock formations having strata of varying hardness.

Another object of this invention is to provide well reaming apparatus having flexible characteristics and cutting means such that a relatively simple structure is provided which will be economical to manufacture and which will have a relatively long operational life.

In accordance with this invention there is provided well reaming apparatus comprising an elongated driven shaft adapted to extend below a well easing into a well bore within a rock formation, and a plurality of reaming cutters attached to said shaft for rotation therewith, each cutter comprising flexible arms extending radially of said shaft and having mounted thereon a plurality of cutting discs whereby rotation of said shaft causes said cutters to engage the wall of said bore and enlarge the diameter thereof.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims:

FIG. 1 is an elevational view, partially in cross section, illustrating the well reaming apparatus as provided in accordance with this invention.

FIG. 2 is a detail, partially in cross section, of the flexible reaming cutter as provided in accordance with this invention.

FIG. 3 is a cross section taken on Line 33 of FIG. 2.

Referring to the drawings, this invention comprises reamer apparatus adapted to be lowered through a conventional well casing 16 which extends from the ground surface through a layer of soil 11, for example, into an underlying rock formation 12. The reamer apparatus comprises a pipe member 14 which extends below the well casing 10 into the well bore 15. Within the pipe 14 there is provided a shaft 17 which may be supported for rotation within bearing members 18 and 19. At the upper end of the pipe 14 there is provided a T-connection 20 threaded or otherwise secured to pipe 14 and providing a support for the bearing 18 together with a connection for pipe 21 which leads to a pump 22. The bearing 19 is in the form of a spider having openings as indicated at 24 so that pump 22 may be operated to pump water out of the well bore as the reamer apparatus is rotated, thereby to remove rock fragments as the bore of the Well is enlarged. Pump 22 may discharge into a settling tank 26 which may overflow through a pipe 27 back into the casing 10, thereby to maintain water within the well While the reamer is operating.

A plurality of flexible cutters or reamers 28 is mounted at spaced intervals along the lower end of shaft 17. It is intended that the shaft 17 shall be long enough to extend to the bottom of the well bore and that there shall be a sufiicient number of cutters 28 to contact the walls of the Well bore in such a manner that a substantial length of the well bore may be enlarged.

Each of the cutters 28 comprises a flexible shaft or arm 29 which may be formed of Wire cable or may comprise any well known flexible shaft material. Shaft 17 is provided with a plurality of transverse bores 30 for receiving each of the flexible shafts 29 at spaced intervals as illustrated in FIG. 1. Shaft 29 supports a plurality of cutter discs 32, each of which includes on its periphery a plurality of cutting teeth 33. Discs 32 are spaced from one another by the spacers 34, and the entire assembly of discs and spacers is intended to be rotatably mounted on the shaft or arm 29 and is forced into engagament with a stop device 36 by means of a spring 37. The stop device 36 may be in the form of a conventional cable clamp or may consist of a disc, for example, welded or otherwise secured to the flexible shaft 29. Spring 37 is compressed between the shaft 17 and the cutter-and-spacer assembly, engaging it at 38 and engaging the shaft 17 at 39 thereby normally to center the cutter of reamers 28 to shaft 17.

For driving shaft 17 and the reamer cutters there 18 provided a motor 41 having a drive gear 42 WhlCh meshes with a gear 43 which, in turn, is fixed to shaft 17. The pipe 14, pump 22 and motor 41 may all be supported on a portable base structure 45, and pipe 14 may be centered within the well casing 10 by means .of a suitable collar 46. It will readily be understood that the reamer apparatus, the pump, and the drive mechanism is intended to be portable so that the complete assembly may be transported from one well to another.

In operation, the reamer apparatus may be inserted within a well, and before the reaming operation is commenced, each of the reamers 28 will assume a fiexed position as indicated in dotted lines at 47. Also, it will be readily understood that the well bore will have a diameter at its lower end as indicated in dotted lines at 48. When the motor 41 is started, the reamers 28 will be rotated and centrifugal force will cause them to engage the rock surface of the well bore. With continued operation the cutter discs 32 chip away the rock, and the chips are removed by operation of pump 22. The operation may be continued until the water being pumped from the well no longer brings up rock chips which will indicate that the well bore has been enlarged to a diameter comparable to the length of the arms 28.

Actual use of the reamer apparatus as provided in accordance with this invention shows that the flexibility of the arms 28 prevents destruction or damage when the arms happen to engage an exceedingly hard layer of rock. It frequently happens that a stratum of rock a few inches in thickness may be much harder than the rock above and below the hard stratum. In this event the flexible arms simply do not remove as much of the hard stratum as would be the case if the particular stratum were relatively soft. Those arms in engagement with the softer rock straighten out in response to centrifugal force and ream out the bore to the full diameter. When cracks are encountered, the flexibility of the arms and the rotational movement of the cutters prevents any damage to the reamers. It is to be noted that the springs 37 permit the reamers to move transversely of shaft 17, and this is an advantage where hard rock is encountered on one side of the bore only. In this event the cutters may move transversely of the shaft 17 and remove more rock on the soft side of the bore than on the hard side.

This invention provides a means for enlarging the Water capacity of a well due to the fact that the portion of the Well bore which is not lined with pipe can be enlarged to increase the storage capacity of the well and, thus, a well which might be capable of delivering only gallons of water during one pumping cycle, is provided with the capacity of delivering '50 gallons or more during a pumping cycle, depending upon the degree of enlargement of the well bore.

The invention claimed is:

1. Well reaming apparatus adapted to enlarge a well bore comprising a driven rotary shaft, and a plurality of spaced reaming cutters attached to said shaft for rotation therewith, each cutter having a length exceeding the diameter of said bore and comprising a flexible arm mounted at its mid-portion transversely of said shaft and having mounted thereon cutting devices engageable with the wall of said bore for enlarging the diameter, said driven shaft including means for mounting the mid-portion of said flexible arm for movement transversely of said shaft, and spring means mounted on said arm in engagement with said shaft and said cutting devices for normally centering said arm transversely of said shaft and permitting movement of said arm transversely of said shaft.

2. Well reaming apparatus adapted to enlarge a well bore comprising a driven rotary shaft, and a plurality of spaced reaming cutters attached to said shaft for rotation therewith, each cutter having a length exceeding the diameter of said bore and comprising a flexible arm mounted at its mid-portion transversely of said shaft, cutting devices rotatably mounted on said arm for engagement with the Wall of said bore for enlarging the diameter thereof, rotatable spacer members interposed between said cutting devices for slidable movement on said arm, and spring means mounted between said shaft and said cutting devices for normally engaging said cutting devices with said spacing members and permitting lateral movement of said cutting devices and said spacers on said arm.

3. Well reaming apparatus adapted to enlarge a well bore comprising a driven rotary shaft, and a plurality of spaced reaming cutters attached to said shaft for rotation therewith, each cutter having .a length exceeding the diameter of said bore and comprising a flexible arm having mounted thereon cutting devices engageable with the wall of said bore for enlarging the diameter thereof, said shaft including means for supporting the mid-portion of each arm transversely of said shaft for transverse movement relative to said shaft.

4. Well reaming apparatus adapted to enlarge a well here comprising a driven rotary shaft, and a plurality of spaced reaming cutters attached to said shaft for rotation therewith, each cutter having a length exceeding the diameter of said bore and comprising a flexible arm mounted at its mid-portion transversely of said shaft and having mounted thereon cutting devices comprising spaced rotatable disc members engageable with the wall of said bore for enlarging the diameter thereof.

References Cited by the Examiner UNITED STATES PATENTS 1,145,418 '7/ 1915 Huelsdonk 263 1,423,625 7/ 1922 Rogers 175291 1,467,480 9/1923 Hogue 175-263 1,558,596 10/1925 DeFontaine 175-263 2,214,982 9/1940 Wylie 175-327 X 2,548,724 4/ 1951 Jones 175-263 FOREIGN PATENTS 41,499 4/1887 Germany.

CHARLES E. OCONNELL, Primary Examiner. 

4. WELL REAMING APPARATUS ADAPTED TO ENLARGE A WELL BORE COMPRISING A DRIVEN ROTARY SHAFT, AND A PLURALITY OF SPACED REAMING CUTTERS ATTACHED TO SAID SHAFT FOR ROTATION THEREWITH, EACH CUTTER HAVING A LENGTH EXCEEDING THE DIAMETER OF SAID BORE AND COMPRISING A FLEXIBLE ARM MOUNTED AT ITS MIT-PORTION TRANSVERSELY OF SAID SHAFT AND HAVING MOUNTED THEREON CUTTING DEVICES COMPRISING SPACED ROTATABLE DISC MEMBERS ENGAGEABLE WITH THE WALL OF SAID BORE FOR ENLARGING THE DIAMETER THEREOF. 